Fiber press control



May 12, 1970 J. c. NEITZEL ET AL FIBER PRESS CONTROL 3 Sheets-Sheet 1 Filed Oct. 11., 1967 ATTOR/Vf) May 12, 1970 J. c. NElTZEL ET AL 3,511,019

FIBER PRESS CONTROL Filed Oct. 11. 1967 I 3 Sheets-Sheet 2 INVEN'IORS rrow/15y H J. c. NEITZEL ET AL 3,511,019

FIBER PRESS CONTROL May 12, 1970 3 Sheets-Sheet 5 Filed Oct.

' 7i 7 b. 4 |||I|-- "7 Z9 M a a; a/ 3 W t L 52 m2 92 k m/ 99 S T 6; M3 T (fame 0b C Nev/ze/ 6 W. .D/cA'J0/7 mvm'rom United States Patent U.S. CI. 53-52 2 Claims ABSTRACT OF THE DISCLOSURE A fiber press is provided in which the pressed material is enclosed within substantially impervious, telescoping box parts. In order to prevent trapping of air within the box parts during high-speed operation of the press, the inward movement of the follow block is automatically delayed, e.g., either retarded or momentarily stopped, as the box parts approach their telescoping relationship to facilitate escape of the trapped air.

BACKGROUND OF THE INVENTION Field of the invention This invention relates to fiber presses, particularly of the type for handling synthetic fibers, and consists particularly in novel means for preventing the trapping of air within telescoping box parts which cover the bale so as to reduce the load on the box board material as well as the press follow block.

Description of the prior art Bales of fibrous material, particularly synthetic fibers, are now sometimes enclosed within protective, substantially impervious boxes of paperboard or the like. This has produced a problem in the high-speed operation of presses which compress the material, in that air trapped between the covering box parts places a heavy expansive force upon these parts so that extra heavy and expensive covering material must be used to resist these stresses. Furthermore, the build-up of air pressure within the telescoping box parts greatly increases the load on the moving platen (follow block). As far as is known, the prior art does not suggest practical solutions for these problems.

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide practical means for relieving the air pressure which otherwise tends to build up within the telescoping box parts as utilized in the above-described fiber pressing operation.

Another object is to provide means for increasing the speed of operation of such a. press at a given horsepower, while reducing the internal expansive stresses applied to the covering box parts and, therefore, permitting the use of lighter weight and less expensive material for these cove ng Parts.

According to the herein-described invention, means are provided for delaying the travel of the movable pressure platen .(follow block) into the press box, just prior to interfitting of the bale-covering box parts. In one form of the invention, the rate of travel of the pressure platen is reduced so as to expedite the escape of air from between the parts. In another form of the invention, the follow block is momentarily stopped at th mentioned position thereof, for the same purpose.

BRIEF DESCRIPTION OF THE DRAWINGS In the accompanying drawings which illustrate the invention,

3,511,019 Patented May 12, 1970 FIG. 1 is a perspective front view of a form of press utilizing the present invention.

FIG. 2 is a partial perspective of the front of the press, certain parts being broken away and the press front door being opened to illustrate internal parts and the bale being formed.

FIGS. 3 and 4 are perspective views of the bale-covering box parts.

FIG. 5 is a view of a finished bale.

FIGS. 6 and 7 are schematic diagrams of two forms of pressure platen operating and control mechanism.

DESCRIPTION OF THE PREFERRED EMBODIMENTS The press shown in FIGS. 1 and 2 is of the stationary box type having rotating boxes beneath the floor level. A massive frame surrounds the boxes including upright side channels 10 and 11, base structures 12 and 13, floor level horizontal bracing 14, and top sill structures 15 and 16. Pivotally mounted on a center post 17 in the lower part of the framing are identical boxes, generally designated [18 and 19, rigidly braced and secured together by cross bars 20-24 inclusive. A relatively light box part, generally designated 28, is mounted at the right side of the framing, above the flooring 27, for directing fibrous material from a tramper structure, generally designated 29, downwardly into the box 18 or 19 which, at the moment, is directly therebeneath. Box 28, of course, is open at the top and bottom. Tramper 29 is of conventional commercial design and need not be further described, except to point out that th tramper consists of a vertically reciprocating foot which periodically pushes fibrous material, fed thereto as from an air separating condenser, downwardly through box 28 into a press box therebeneath.

At the left side of the framing structure, above the flooring, there is provided a heavy press box, generally designated 32. This box has a front door 33 which is hingedly mounted on an intermediate heavy vertical beam 34 and which may be locked in its closed position by clamping mechanism, generally designated 35. As shown in FIG. 2, door 33 has an intermediate horizontal ledge 36 on its inner face which is horizontally aligned with similar ledges as at 37 on the end walls, and also the rear door.

Depending from heavy base structure 12 into a well 38 are a pair of hydraulic cylinders 40 in which reciprocate pistons (not shown) from which piston rods 41 extend upwardly and carry at their tops a pressure plate 42 which underlies the beams 43 of the pressure platen or follow block, generally designated 44. Bale engaging bars 45, usually of wood, traverse beams 43. Follow block structure 44 in the lowered position of the ram, formed by cylinders 41, etc., rests at the bottom of its box 19 on bottom framing parts 20 and 46. At the top of press box 19 there is provided the stationary upper platen structure 47 which is rigidly secured and rests against upper sill structure 15. Boxes 18 and 19 may be rotated through the intermediary of gearing 48 and other mechanism (not shown)..

FIG. 6 is a schematic diagram of a control arrangement including a hydraulic motor 50 which is representative of the ram forming hydraulic cylinders 40 from which project piston or plunger rods 41. Hydraulic fluid lines 51 and 52 extend from the upper and lower parts of motor 50 to connections 53 and 54 and 55 and 56 of pumps P and P through check valves 57 and 58. Pumps P and P are, respectively, a high volume low pressure pump (P and a low volume high pressure pump (P These pumps and valving constitute an hydraulic staging system, as will be explained. The pumps are provided with operating motors M and M having control wiring 59 and 60 and 61 and 62. This control wiring passes through reversing switch mechanisms, generally designated 63 and 64, having actuating plungers or levers 65 and 66 (conveniently linked together). The reversing switches are connected respectively through Wires 67 and 68 to microswitches 69 and 70 which are in turn connected by wires 71 and 72 to power sources 73 and 74. While batteries are shown, it will be understood that normally the power source will be the power lines connected to the plant. Ground or common return leads 75 and 76 also connect with the reversing switches. Startstop switches for the ram motors are shown at 77 and 77a. Projecting from one of the plunger rods 41 is a detent member 78 which is disposed to actuate an over-center lever 79 having a microswitch actuator extension 80.

FIG. 7 shows a modified control mechanism in which piston rod carried detent 78 is positioned to actuate over-center lever 79 with a microswitch actuating extension 80, as in FIG. 6. However, only a single microswitch 81 is provided which is connected by a wire 82 to an operating motor 83 of a timer switch 84. The timer switch terminals are connected by a Wire 85 to a source of power 86 which is connected by a wire 87 to timer motor 83. This circuit leads through wire 82 and microswitch 81 to a common return wire 88.

The other lead 89 from timer switch 84 connects with reversing switch 101 to which is connected a ground or common return lead 90. The reversing switch has an actuating lever 91 and connects by wires 92 and 93 to a motor M which drives pump P which is connected by hydraulic lines 94 and 95 to hydraulic motor 96 which, as in FIG. 6 symbolizes the hydraulic cylinders 40 of the hydraulic ram.

FIG. 2 also shows an upwardly-opening box part 97 (also shown in FIG. 4) resting on bottom platen 44, and a downwardly-opening top box part 98 (also in FIG. 3) resting against top platen 47 and supported upon the horizontal ledge in the inner faces of the doors and end walls at the top of press box 19.

In operation of the press equipped with the control mechanism of FIG. 6, after the box part 18 beneath the tramper 29 (FIG. 1) is filled with the proper amount of fiber, the boxes are reversed to bring box 18 above base structure 12 and the ram. Reversing switch plunger or lever 65 and switch 77 are then actuated to cause operation of pump P in the direction for driving plunger rods 41 and the now superimposed follow block rapidly upwardly to compress the fiber in the box. When follow block 44 reaches the position shown in FIG. 2, with box parts 97 and 98 approaching but not yet telescoped together, detent 78, which moves with the ram structure, engages and rotates over center lever 79 to the position shown in FIG. 6 for actuating normally-open microswitch 70 and opening switch 69. Current is then transmitted through reversing switch 64 to motor M for driving high pressure pump P At the same time, microswitch 69 is permitted to open to cut off the supply of current to motor M so that upward motion of bottom platen 44 is sharply retarded and continues at a reduced rate of speed. Preferably, the first major part of the press movement of the ram is at a high rate of speed under the influence of high volume pump P while the last portion of this movement of the ram is at a much lower rate which permits the escape of air trapped between the box parts. This has the effect of reducing the internal pressure on the box walls, which permits the box parts to be made of lighter, less expensive materials, and also reduces the back pressure on the platen and ram structure.

- After the pressed and covered bale is bound with baling straps, as at 100 in FIG. 5, the platen will be withdrawn somewhat, the doors opened, and the end walls withdrawn to permit removal of the finished bale. Thereafter, ram reversing switch levers 65 and '66 are actuated to initiallyv lower platen 44 by means of pump P until detent 78 again rotates over center lever 79 to open microswitch 70 and close microswitch 69 causing energization of high volume pump P and final lowering of the platen struc- 4 ture at the corresponding high rate of speed. Of course, the rate of final lowering of the platen may be varied from the rate of initial lifting thereof, if desired.

In the use of the control apparatus of FIG. 7, the retarding of the press movement of the lower platen from the position shown in FIG. 2 is achieved by momentary stopping of the platen. At the lower platen position of FIG. 2, detent 78 engages and rotates over center lever 79 so as to close normally-open microswitch 81. This causes energization of a timer motor 83 which starts the actuation of normally-closed timer switch 84. When the timer leaves its normally-closed, energized position, power from source 86 is cut off from reversing switch 101 and motor M so that pump P is stopped. At the same time, upward movement .of piston rods 41 is arrested. At the end of the predetermined timed interval, timer switch 84 reassurnes its normal energized position and current is again passed from source 86 to motor M to complete the upward movement of the press follow block. As will be understood, the extreme movement of the press platen is ended, either automatically or otherwise, through the intermediary of a switch, as at 102, suitably placed in the circuit.

During the downward movement of the ram structure and press platen, lever 79 will be oppositely rotated to reopen switch 81 so that the press will continue downwardly at an unabated rate.

Accordingly, with the use of the above-described invention, air pressure within the interfitting box parts will be relieved as to achieve the advantages heretofore stated. The. control circuitry is merely illustrative and may be modified, as may various features of the press, as will occur to those skilled in the art. For instance, the lowering of the press ram may be at a uniform rate and under the influence of gravity. The exclusive use of all modifications as come within the scope of the appended claims is contemplated.

We claim:

1. The combination in a fiber press having a press chamber; fixed and movable platens, respectively, at the top and bottom thereof; upwardly and downwardly open ing, telescoping, interfitting box parts for resting, respectively, against said platens, said box parts comprising impervious sheets; means for charging said chamber between said box parts with the material to be. pressed; a fluid operated ram and fluid pressuring apparatus con nected thereto for moving said bottom platen upwardly into said chamber to press said material therein; control means being operatively connected to said fluid pressuring apparatus and including a control device movable with said bottom platen and cooperable with said ram at a predetermined position of said bottom platen and including means in said chamber and on said ram shaped to partially trap air therebetween after said ram passes said position during its inward movement and in which said control device functions to reduce the build-up of air pressure in said chamber and the resultant resistance to movement of said ram, for delaying the rate of travel of said bottom platen as said upwardly opening box part approaches said downwardly opening box part to facilitate the escape of the air partially trapped between said box parts as said box parts are caused to telescope.

2. The combination in a fiber press having a press chamber; fixed and movable platens, respectively, at the a predetermined position of said bottom platen and including means in said chamber and on said ram shaped to partially trap air therebetween after said ram passes said position during its inward movement and in which said control device functions to reduce the build-up of air pressure in said chamber and the resultant resistance to movement of said ram, for momentarily stopping the travel of said bottom platen as said upwardly opening box part approaches said downwardly opening box part to facilitate the escape. of the air partially trapped between said box parts as said box parts are caused to telescope.

References Cited UNITED STATES PATENTS 2,485,040 10/1949 Cupo 53381 X 3,123,958 341964 Carruthers 53124 3,213,587 10/1965 Carruthers 5324 X 3,307,320 3/1967 Harriss 5324 3,330,089 7/1967 Uematsu 53-24 6 1,897,612 2/1933 Helfrecht 53-52 2,481,611 9/1949 Moore 53-124 2,525,310 1/1953 Davis 53-l24 2,763,203 9/1956 Russell 53-124 3,405,744 10/1968 Bowman 53124 3,413,913 12/1968 Smedlund 53l24 3,424,078- 1/ 1969 Boyd 53124 FOREIGN PATENTS 908,447 4/ 1954 Germany.

OTHER REFERENCES White, Def. Pub. of SN. 663,321, filed Aug. 25, 1967, published in 857, O.G. 1039, Dec. 24, 1968, 53-124.

WAYNE A. MORSE, JR., Primary Examiner U.S. Cl. X.R. 5324, 124 

